Mankiw is a harvard economics professor and sometimes adviser to Republican politicians.

The link is to an article in Barron's in which Jim McTague makes the observation that Obama raised expectations impossibly high with all of his promises of alternative energy and so-called "green jobs":

Obama's mistake was to advertise himself as a hi-tech guru with the added, superhuman ability to manipulate market forces to create a green-energy utopia where batteries, algae and solar cells would replace climate unfriendly fossil fuels like coal and gasoline. His lengthy litany of powers included the ability to raise the cost of these dirty fuels to reduce their pricing advantage over renewable energy. He harped that this was desirable and necessary.

The political imprinting worked better than our president ever imagined. Now that gasoline prices are pinching pocketbooks, the public expects Obama to exercise his superpowers and manipulate prices lower. Protestations by Obama that market forces beyond his control are setting the prices are greeted with disdain rather than sympathy.

He goes on to note the central insight of the Pigouvians: Consumption taxes are preferable to income taxes. No one wants to tell the votres that, but it's true. From the perspective of a free-market advocate, taxing consumption is infinitely preferable to taxing work, which is what the income tax does.

Also, a tax works much better in achieving whatever goals are desired:

Harvard University economist Greg Mankiw, currently an advisor to GOP presidential hopeful Mitt Romney, has long been an advocate of a $1-per-gallon gas-tax hike phased in over 10 years (Romney won't countenance the tax). Absent the tax, politicians resort to crazy, Obama-like schemes to achieve the same end of reducing our dependence on foreign oil supplies.

MANKIW PRESCIENTLY STATED during a 2006 interview conducted by CNBC's Larry Kudlow that the alternative to a simple gas tax is "an energy policy that looks like it was created in the Kremlin."

"An alternative in Washington to gas taxes," he said, "is very heavy-handed regulation that's extraordinarily intrusive and not particularly effective. Things like CAFE standards"—the fuel-efficiency rules that auto manufacturers are required to follow—"and biofuel mandates are tremendously regulatory. The gas tax is really the least invasive way of getting toward our energy goals."

In an Oct. 20, 2006, op-ed piece in The Wall Street Journal, Mankiw said higher gasoline taxes would be the least invasive way to reduce pollution and highway congestion. The tax would encourage manufacturers to make fuel-efficient cars and eliminate the need for bureaucratic mandates. Mankiw estimated in his 2006 article that tax revenue would amount to $100 billion a year, which could be used to lower the deficit.

Mankiew is right, of course. But no politician would dare tell the voters this simple truth. That's because politicians, even conservative ones, all feel obligated to shed crocodile tears for the "poor" people who would be hit with that tax.

I can see why a liberal would support such an argument. But conservatives should argue the exact opposite. The bottom half of the populace pays no income tax. If they're not going to pay on April 15, then let them pay every time they fill up their cars.

We could eliminate a lot of the national debt and also reduce oil imports.

Don't expect that from either candidate, though. At the moment we're going to hear promises of cheap gas till November.